Downy mildew

Contributor: Aarhus Universitet
Date Compiled: 2025
Creative Commons "Attribution-Share Alike"
Bremia lactucae (downy mildew of lettuce); Initial and later symptoms. Image copyright: ©Dr Philip Taylor (CABI)

Prevention

Solution Production stage (if possible with reference to BBCH scale)
Wide crop rotations
Pre-season
Destroy residues of diseased crops
Pre-season
Increase soil drainage
From Sowing/Planting to Harvest
Reduce crop density
Sowing/Planting
Using resistant verieties
Sowing/Planting

Control

Regulations surrounding chemical products can change rapidly – always verify chemicals recommended here with the most recent legislation and lists of products registered for your country
Solution Product Category Production stage (if possible with reference to BBCH scale) Max nb. of a. i. application/year Application Details and Notes (commercial product example) Chemical Group Risk resistance (FRAC Code)
Mandipropamid
Synthetic fungicide
Start of treatments since there are favorable conditions for the development of infection. Suspend treatments 7 days before harvest
4 (1 intervention per crop cycle)
(PERGADO SC®) Dosage: 0,6 L/ha
CAA-fungicides (Carboxylic acid amides)
Resistance known in Plasmopara viticola but not in Phytophthora infestans. Cross resistance between all members of the CAA group. Low to medium risk. (40)
Propamocarb
Synthetic fungicide
Start of treatments since there are favorable conditions for the development of infection. Suspend treatments 7 days before harvest
2 (per crop cycle)
(PREVITER) Dosage: 1,5 L/ha
Carbamates
Low to medium risk (28)
The information made available here has been obtained from or is based upon sources believed by CABI to be reliable but is not guaranteed as to accuracy or completeness. Anyone acting or relying on such information does so entirely at their own risk. The efficacy of the IPM methods included above will depend on local conditions and might not always be suitable everywhere within the specified country.